LCD (liquid crystal displays) use a linear polarizer and a circular polarizer to control the optical rotation and the birefringence in the display. OLED (organic EL elements) also use a circular polarizer to prevent external light reflection.
Conventionally, polarizing layers obtained by dissolving or adsorbing iodine or a dichroic organic dye in or to a polymer material such as polyvinyl alcohol and uniaxially stretching a film of the resultant to orient the dichroic dye have been widely used for the polarizers (polarizing elements). However, the conventional polarizing layers produced in the above manner have the problems of, for example, inadequate thermal resistance and inadequate light fastness depending on the dye and the polymer material used, and a low bonding yield of the polarizing layers in the production of a liquid crystal device. Attempts have been made to form a polarizing layer in a cell to achieve brightness enhancement by simplifying the structure of the elements.
Methods for applying a solution that includes a dichroic dye onto a substrate such as a glass sheet or a transparent film to form an anisotropic dye coating for use as a polarizing layer are also discussed. Examples of the methods for producing an anisotropic dye coating by such application process include a method of forming plural patterns on a single substrate. For example, a method of forming patterns by disposing a layer that includes a photocatalyst on a substrate and irradiating the layer with energy (Patent Document 1), a method of forming patterns by controlling application of an anisotropic dye coating by varying hydrophilization of a substrate (Patent Document 2), a method of forming patterns by selectively insolubilizing an anisotropic dye coating (Patent Document 3) have been proposed. A method of forming patterns by disposing a layer that includes a photosensitive resin layer on an optically anisotropic layer, exposing the layer through a certain mask, and developing the layer (Patent Document 4) has also been proposed.